Sunday 9 July 2006 06.13 EDT
First published on Sunday 9 July 2006 06.13 EDT

ZaideBarbican, London EC2

Cosi Fan TutteHolland Park, London W8, until Saturday

The Original Chinese ConjurorAlmeida, London N1

The contentious American director Peter Sellars has cast Mozart's Don Giovanni as a Harlem drug baron and set Cosi Fan Tutte in a Cape Cod diner. Now he has reinvented an early operatic fragment, Zaide, as a tract inveighing against 21st-century slavery. There are more slaves in the world today, according to a half-hour lecture before it started, than there were in Abe Lincoln's time. Swap the harem Mozart had in mind for a Third World sweatshop, and this early, unfinished work, written when Mozart was 23 but never performed in his lifetime, becomes a piece of campaigning opera.

On the first anniversary of the 7 July bombings, Sellars even drew the Muslim world, and its relationship with Europe, into Mozart's impassioned defence of personal freedom. By stitching in passages from a simultaneous, also unfinished piece, Thamos, King of Egypt, he meanwhile bulked out 75 minutes of music into an evening of almost three hours.

The overture and interludes from Thamos, craftily used by Sellars to advance the action, often made for more interesting listening than Zaide itself, little-known apart from the exquisite aria at its beginning, 'Ruhe Sanft', a standard soprano showcase. It is as heartfelt as anything Mozart wrote, but often less than dramatic.

Feeling his way from German Singspiel towards Italian opera buffa, Mozart compromised with a series of testing, set-piece arias, one duet, one trio and a concluding quartet that point the way past Seraglio to the three great Da Ponte operas. This was the fascination of the evening, listening to half-formed Mozart fighting out of its shell, as Sellars tried to breathe contemporary life into a mundane tale of escape and revenge. He benefited hugely from Mozart's failure to finish the work, lending its unresolved ending an elliptical modern twang.

Already seen in Vienna, Zaide travels to New York with a fine cast led by Hyunah Yu, with strong performances from the tenors Norman Shankle and Russell Thomas and the bass Alfred Walker. Louis Langree coaxed as much drama as he could from the Concerto Koln. By the end, however, Sellars's claims for the work as 'an anti-slavery opera for the 21st century' were looking (and sounding) overstated.

Mozart called Cosi Fan Tutte a dramma giocoso, but the work is so dark that the humour must be, too. In an otherwise intelligent staging for Holland Park, Annilese Miskimmon opts for seaside-postcard larks - and far too many of them, with the stage cluttered by extraneous characters and objects, to the point where the principals have to fight for our attention as Don Alfonso's cruel con-trick unfolds.

The girls get stuck in the lift before they've even entered. The suitors play golf, the Albanians with butterfly nets. A suffragette is arrested as the Salvation Army wanders in from Guys and Dolls; there are parrots and monkeys and a Punch and Judy show - ah, what has any of this to do with Mozart's Enlightenment take on head versus heart?

At least Miskimmon left Sarah-Jane Davies' Fiordiligi alone onstage to give 'Per Pieta' the prominence it deserves. Curran shares the evening's vocal honours with Lillian Watson's Despina, while Leo Hussain sets a cracking pace in the pit, occasionally leading the City of London Sinfonia into unwonted errors. The audience loved it; but, for me, Cosi is not the work to turn into an end-of-the-pier romp.

That's the scenario for The Original Chinese Conjuror, given its London premiere by Almeida Opera. Those who think that contemporary music can lack a sense of humour - Heaven forfend - will be reassured by Raymond Yiu's entertaining 'musical diversion'.

To a lively libretto by Lee Warren, this cleverly structured and staged (by Martin Duncan) work tells the colourful story of William Robinson, who made it big in Edwardian London by stealing the act of a Chinese magician. He also stole from his mentor, Alexander Herrmann, the trick of catching a bullet between his teeth - which eventually leads to his comeuppance for all this con-trickery.

What aspires to be a homily on fakery and illusion is in truth a slick, pacy vaudeville conducted with due zest by Tim Redmond. Yiu's score is a melange of influences from Sondheim to Stravinsky, yet delightfully breezy and confident. As are the central performances, from Richard Morris as Robinson, Sophie-Louise Dann as his wife-cum-assistant and Paul Leonard as Herrmann.